Apparatus for stirring grain and similar particulate material



APPARATUS FOR STIRRING GRAIN AND SIMILAR PARTICULATE MATERIAL.

Filed July 24, 1961 H. A. KALKE Nov. 10, 1964 2 Sheets-Sheet 1 FIGI WW 1 M INVENTOR.

. HENRY A. KALKE FIGZ fi ATTORNEYS H. A. KALKE 3,156,541

APPARATUS FOR STIRRING GRAIN AND SIMILAR PARTICULATE MATERIAL Nov. 10, 1964 2 Sheets-Sheet 2 Filed July 24, 1961 INVENTOR.

HENRY A. KALKE 5% W0. A ATTOR NEYS United States Patent 3,156,541 APPARATUS FOR STG GRAIN AND SIMILAR PARTICULATE MATERIAL Henry A. Kellie, RFD. 2, Rockford, Iowa Filed July 24, 1961, Ser. No. 126,190 4 Claims. (ill. 3418l) This invention relates to apparatus for stirring grain and similar particulate material, e.g., coffee beans and the like, and more particularly to apparatus for stirring and mixing moist grain as heated or dehumidiiied air is forced upwardly through grain piled in a storage bin.

It currently is common practice to store moist grain in large metal bins or containers and subsequently reduce the moisture content of the grain by forcing air which has been dried or heated, or both, upwardly through the grain. As the air passes upwardly through the grain it picks up moisture from the lower portion of the pile of grain and may become saturated with moisture prior to its discharge from the upper end of the bin. As a consequence, the grain at the upper portion of the pile is the last to be dried and it not infrequently happens that the upper portion of the pile of grain becomes somewhat crusty. When this occurs air passing through the pile of grain is likely to form cracks or channels through the crust and through which the drying air passes, resulting in incomplete bathing of the grain particles with the drying air and, consequently, incomplete and non-uniform drying of the grain. I-leretofore it has been necessary for a workman to enter the storage bin following the formation of a crust and manually break up the crust. Manual operations of this kind not only are difficult and laborious but also are objectionable since they do not necessarily follow a definite and controlled order or pattern with a result that not all of the crust may be broken up or, alternatively, the crust may not be broken up uniformly.

An object of this invention is to provide apparatus which mechanically and automatically stirs or agitates grain or the like in a drying bin so as to avoid or minimize the formation of a crust at the upper portion of the pile.

Another object of the invention is to provide apparatus of the character referred to which traverses a predetermined path that is calculated to effect substantially uniform treatment of all the material at the upper portion of the pile.

A further object of the invention is to provide agitating and stirring apparatus which effects a mixing of the material at the upper portion of a pile with material at a lower level in the pile so as to accelerate the drying.

Another object of the invention is to provide stirring and agitating mechanism of the character referred to wherein the agitating means tends to drive itself in a predetermined path, thereby enabling relatively small and inexpensive driving machinery to be used.

A further object of the invention is to provide adjustable stirring and agitating means for use in drying systems, the adjustability of the agitating means enabling the latter to function efficiently with multiple varieties of material and under varying conditions of moisture content.

Gther objects and advantages of the invention will be pointed out specifically or will become apparent from the following description when it is considered in conjunction with the appended claims and the accompanying drawings, wherein:

FIGURE 1 is a vertical sectional view through a grain storage and drying bin and illustrating agitating and stirring mechanism formed in accordance with the invention;

FIGURE 2 is a top plan View of the agitating and stirring mechanism mounted within the container, the top of the container being removed;

FEGURE 3 is an enlarged view of the stirring and agitating mechanism, partly in front elevation and partly in section;

FIGURE 4 is a sectional view taken on the line 4-4 of FIGURE 3;

FIGURE 5 is a sectional view taken on the line 55 of FIGURE 3;

FIGURE 6 is an enlarged, sectional detail and taken on the line 6-6 of FIGURE 3.

The invention will be described with reference to the stirring of grain during drying, but it is intended that it be understood that the invention has utility in the stirring of other particulate substances, for example coffee beans. Referring to the illustrated embodiment of the invention, a grain storage bin of the kind with which apparatus formed in accordance with the invention is adapted for use is designated generally by the reference character 1 and comprises a preferably cylindrical, upstanding wall 2 supported on a suitable foundation 3. The wall 2 supports a false bottom or floor 4 which is vertically spaced from the foundation to provide a plenum chamber 5 into which air may be introduced. The floor 4 is reinforced by suitable joists ti which may be welded or otherwise fixed to the bin wall 2, and between the joists 6 the floor may be provided with a plurality of apertures (not shown) through which air may pass. The floor defines the bottom of a storage chamber '7 and the upper surface of the floor may be covered by a fine mesh screen 8, the openings in the screen being of such size as to prevent grain from falling into the plenum chamber 5 from the storage chamber 7.

At the upper edge of the wall 2 is a plurality of upwardly and outwardly inclined supporting brackets 9 to which a substantially frusto-conical roof 19 may be bolted or welded. As is indicated in FIGURE 1, there is a space between the roof and the upper end of the wall 2, the space being provided to form means for ventilating the interior of the storage container. An additional ventilating opening 11 may be provided at the apex of the roof 1i) and this opening may be shielded by a cap 12 that is supported on the roof by means of legs 13 or the like.

Grains such as shelled corn, for example, may be introduced to the storage compartment 7 through an opening (not shown) in the roof 10 and may be piled within the bin to a suitable depth. Such grain usually is introduced to the bin in an excessively moist condition, necessitating its being dried in order to avoid spoilage. It has been proposed heretofore to dry the grain by passing drying air through the pile or body, and apparatus constructed in accordance with the invention includes means for introducing air to the plenum chamber 5 and forcing it upwardly through the grain. The air supply means cornprises a motor driven pump 14 having its suction side in communication with an air inlet duct 15 and its pressure side in communication with a discharge duct 16 which is joined to and communicates with a duct 17 leading to a dehumidifying or heating unit 18 which either dries or heats, or both, air discharged by the pump 14. The unit 118 communicates with the plenum chamber through a duct 19 by means of which dried air is introduced to the chamber 5 and at sufficient pressure to cause the air to force its way upwardly through the openings in the false bottom 4 and through the grain for ultimate discharge through the vents at the top of bin 1.

Adjacent the upper end of the storage bin 1 is a primary support, as shown a rotatable or movable bridge structure 20 comprising a pair of substantially parallel angle iron members 21 and 22 having upright flanges 23 and 24, respectively, that form rails extending substantially diametrally of the bin. Intermediate their ends the rails 23 and 24 may be provided with openings through which a stabilizing bar 25 extends (see FIGURE 2). The bar 25 is rigidly fixed to the members 21 and 22 by gussets 26 or the like. At each end of the bar 25 is journaled a flanged wheel 27 which rides upon a circular track or rail 28 that is welded to angle brackets 28a which in turn may be welded to the inner surface of the container wall 2 at such a level as to support the rail 28 and its associated structure above the level of grain piled in the bin. The construction and arrangement of the parts of the agitating apparatus thus far described are such that the bridge members 21 and 22 and the stabilizing member 25 may be rotated relatively to the container 1 about an axis of rotation located substantially at the center of the container.

Means is provided for driving the bridge structure 20 and comprises a combined electric motor and gear reduction unit 29 of known construction that is fixed on a base 3% which may be welded or bolted to the bridge members 21 and 22. The driving unit 29 has a drive shaft on which is fixed a pulley 31 around which is trained a drive belt 32. The belt 32 also is trained about a pulley 33 journaled on one end of a shaft 34 which is fixed to the bridge member 23 by means of U-bolts 35 that are secured to the horizontal flange of the member 21. Fast with the pulley 33 is a double flanged drive wheel 36 which rides upon the rail 28. A guide wheel 37 is journaled on a shaft 38 which is secured to the opposite end of the member 21 by U-bolts 39 that are similar to the U-bolts 35, and a similar guide wheel 37a is journaled on a shaft 38a that is fixed to the bridge member 22 by similar U-bolts 39a. The wheels 37 and 37a also ride upon the rail 28. The arrangement is such that rotation of the drive wheel 36 by the drive unit 29 will cause the entire bridge assembly 20 to be rotated slowly in a counterclockwise direction, as viewed in FIGURE 2.

Grain agitating or stirring mechanism constructed in accordance with the invention is designated generally by the reference character 40 and comprises a secondary support, in the form shown an open, rectangular carriage 41 having parallel frame members 42 joined at their opposite ends to cross frame members 43. To the frame members 42 are Welded or otherwise fixed bearing supports 44 which receive and journal axles 45 on which flanged wheels 46 are mounted. The wheels 46 ride upon the respective bridge rails 23 and 24 so as to permit the carriage 41 to be shifted radially inwardly and outwardly relatively to the axis of rotation of the bridge assembly 20.

Means for shifting the carriage 41 comprises a shaft 47 which parallels the bridge member 22 and has its radially inner end journaled for rotation in a bearing support 48 that is fixed to the member 22. The other end of the shaft 47 extends through a cylindrical bearing support 49 and is fixed to an operating, double flanged wheel 50 which rides on the rail 28. Over a substantial portion of its length the shaft 47 is provided with oppositely pitched, helical grooves or threads 51, 52 which merge with one another at opposite ends of the threaded shaft portion in a known manner. The threaded portion of the shaft 47 extends through an annular nut element 53 that is clamped by bolts 54 to a bracket 55 that is welded or otherwise suitably fixed to one of the frame members 42 of the carriage 41. The nut element 53 is equipped with a thread follower or dog 56 that is received in one or the other of the threads 51, 52 and is rockably mounted in the nut 53 by means of a post 57 that rotatably projects into an opening 53 formed in the member 53. The construction and arrangement are such that the dog 56 follows one of the threads 51, 52 upon rotation of the shaft 47 in one direction, thereby driving the carriage in one direction radially of the bin 1 until the dog reaches one end of the thread, whereupon further rotation of the shaft in the same direction causes the dog to enter the other thread. Further rotation of the shaft in the same direction then will cause the carriage 41 to traverse the threaded portion of the shaft in the opposite radial direction. Rotation of the shaft 47 is effected by rotation of the wheel 56 in response to rotation of the bridge structure 20.

The extent of the threaded portion of the shaft 47 is such as to cause the carriage 41 and parts yet to be described to be capable of traversing substantially the entire radius of the bridge structure for a purpose presently to be explained.

The stirring or agitating mechanism includes a boring auger 59 comprising a shaft 60 to which is fixed a spiraling flight 61. The flight 61 may taper to one end of the shaft 63 but terminates short of the other or upper end of the shaft. The upper end of the shaft extends through a bearing 62 that is supported in a substantially U-shaped bearing support 63 which is located within the opening in the carriage 41 and is welded or otherwise suitably fixed to a plate 64. The plate 64 is adjustably mounted on the carriage 41 by means of a hinge 65 and the plate may be fixed in any selected position of adjustment by means of anchor bolts 6511. which are pivoted as at 66 to the frame member 42 and which pass through slots 67 in the plate 64. Nuts 68 located on opposite sides of the plate 64 may be manipulated to fix the plate 64 in a selected position of angular adjustment. The angular position of the auger 59 will depend on a number of factors, such as the depth to which the auger extends into the grain, the degree of moistness of the grain, and the speed at which the apparatus is operated.

The plate 64 is apertured to receive the upper end of the shaft 66, the latter being rotatably journaled in a bearing 69 carried by the plate. Means for rotating the auger 59 comprises an electric motor 70 mounted on a supporting bracket 71 which is fixed in a suitable manner to the adjustable plate 64 so as to be adjustable with the latter. The motor includes a shaft 72 on which is fixed a pulley 73. A driving belt 74 is trained around the pulley 73 and around a pulley 75 that is fixed to the auger shaft 60. The direction of drive of the motor 70 should be such as to cause rotation of the auger 59 in a boring direction, i.e., clockwise as is viewed from above in FIGURE 4.

The connection of the driving units 29 and 70 to a source of electric energy may be made in any suitable manner. For example, current conducting wires 76 and 77 connected to and extending from the drive units 29 and 70, respectively, may be fixed to a rotatable commutator or slip ring coupling 78 that may be suspended from the roof cap 12 by means of a post 79. Wires (not shown) may be strung from the coupling element 78 to a source of energy.

When the apparatus is in condition for operation, the storage bin 1 will contain grain to a suitable level which is below the level of the rotatable bridge structure The auger 59 will extend into the top surface of the grain and to a desired level or depth, but it usually is not necessary to extend the auger into the grain more than about half the depth of the pile. The depth to which the auger is extended into the pile will depend upon the kind of grain or other material being treated, the moisture content of the material, and the speed and frequency of operation of the stirring and agitating mechanism. If

desired, the auger 59 may be made longitudinally adjustable relatively to its supporting structure such as by the use of extensible sections above the auger flight or in any other suitable Way.

Operation of the blower 14 may begin at any time after the perforated floor 4 is covered with grain and be continued for as long as is desired. Opeartion of the stirring and agitating mechanism may begin at any time after the level of the grain in the bin is above the lower end of the auger, and the agitating apparatus may be operated continuously or intermittently as conditions require.

In operation, the auger driving motor 70 rotates the auger in a boring direction, causing the flight 61 to lift grain from a lower level to a higher level while grain adjacent the fiight falls into the space created by the elevating of the grain. In this manner grain from a lower portion of the pile is raised to and mixed with grain at the top of the pile.

Concurrently with the driving of the auger, the bridge structure driving unit 29 is operated so as to cause rotation of the bridge structure unidirectionally, e.g., counterclockwise, as is viewed in FIGURE 2. The rotation of the bridge structure will cause the apparatus 40 also to be rotated in an orbital path about the bin and, at the same time, rotation of the wheel 50 will cause rotation of the shaft 47 so as to effect radial movement of the apparatus 40. If the agitating and stirring apparatus initially is in the position shown in FIGURES 1 and 2, the auger 59 will be at the radially outermost position when the driving units are actuated. Thus, the bridge structure will be rotated slowly in a counterclockwise direction and, simultaneously, the apparatus 40 will begin to move radially inwardly so that the auger moves in a gradually spiraling or orbital path of ever decreasing diameter thereby varying the radius of the orbital movements. When the auger and its supporting structure reach their radially innermost position the thread follower 56 will pass from one groove 51, 52 of the threaded shaft 47 into the other groove so as to effect driving of the apparatus 40 in the opposite direction, i.e., radially outwardly. Thus, during continued rotation of the bridge structure in a counterclockwise direction, the auger will be moved in a spiraling path of ever increasing diameter. When the auger and its supporting structure reach their radially outermost positions, the thread follower $6 and shaft 47 will effect another reversal of radial driving of the apparatus 40 so that it will move radially inwardly and trace a spiral path of ever decreasing radii. In this way, the auger 59 will serially trace a spiral path of ever decreasing radii followed by tracing a spiral path of ever increasing radii, will then repeat tracing a path of ever decreasing radii followed by tracing a path of ever increasing radii, and so on.

As had been pointed out hereinbefore, the length of the threaded portion of the shaft 47 is such as to permit the apparatus 40 to traverse substantially the entire radial dimension of the bin. Consequently, the entire upper portion of the pile of grain will be treated uniformly to prevent the formation of a crust at the upper end of the pile.

In a typical installation the bin 1 may have a diameter of eighteen feet and grain may be piled in the bin to a depth of about twenty feet. The auger may extend into the grain to a depth of about ten feet and be driven at a speed of approximately three hundred sixty-seven revolutions per minute. The bridge structure 20 preferably is driven at a speed of about two-thirds revolution per minute and the pitch of the threads formed in the shaft 47 preferably is such that it requires seven or eight revolutions of the bridge structure for the carriage 41 to make one traverse of the threaded portion of the shaft. If the diameter of the auger flight 61 is about four inches, the successive convolutions of the auger path through the grain will be closely adjacent one another so as to assure a complete and substantially uniform agitation of the upper portion of the pile of grain. If desired, the arrangement can be such that the convolutions of the augers path will overlap.

An important characteristic of the invention resides in inclining the auger 59 so that it extends into the grain in the direction of its orbital movement. Stated differently, the auger is downwardly inclined to the vertical and is tangential to the spiral path it follows. The anger is not inclined toward the axis of rotation of the bridge structure 20. The inclination of the auger has certain advantages such as relieving the bending forces imposed on the auger by its being driven through the grain. Moreover, the inclination of the auger in the manner described, coupled with its rotation in a boring direction, results in a reaction between the auger and the grain which tends to propel the bridge and its associated structure in the direction of inclination of the auger. As a consequence, the drive unit 29 can have a much smaller rating or capacity than otherwise would be required. In some instances, the reaction forces between the auger and the grain may be of such magnitude as to make it possible to eliminate the drive unit 29 altogether, in which event the supporting structure for the agitating apparatus would be rotated solely by the latter.

Under normal conditions of moisture content of a grain such as corn, it has been found that inclination of the auger 5? at 30 provides a satisfactory balance of forces reacting between the grain and the auger. That is, at about 30 inclination, the reaction between the auger and the grain enables a material force to be exerted on the bridge structure, tending to rotate it in the manner previously described while avoiding the imposition of substantial bending forces on the auger shaft 60. For different grains or for different moisture conditions of any of the grains, it may be desirable to vary the inclination of the auger. Thus, in the illustrated construction, the inclination of the auger may be varied between the limits of about 20 and 5 to the vertical by manipulation of the adjustable mounting plate 64 in the manner previously described.

The disclosure of preferred methods and apparatus is intended to be illustrative of the invention rather than definitive thereof. The invention is defined in the claims.

I claim:

1. Grain storing and drying apparatus comprising a bin having a perforated bottom on which grain may be piled; air drying means; means for forcing dried air through said perforated bottom and through the pile of grain; grain stirring means; means mounting said stirring means for spiralling movement through said grain about a vertical axis within said bin; driving means for revolving said stirring means about said vertical axis in a single direction of revolution; and means operable while said stirring means is revolving about said axis for serially moving said stirring means radially toward and radially away from said axis whereby said stirring means will serially trace a spiral path of ever decreasing radii followed by tracing a spiral path of ever increasing radii, will then repeat tracing a path of ever decreasing radii followed by tracing a path of ever increasing radii, and so on.

2. The apparatus set forth in claim 1 wherein said stirring means comprises a rotatable boring auger.

3. Grain storing and drying apparatus comprising a bin having a perforated bottom on which grain may be piled; means for forcing drying air through said perforated bottom and through the pile of grain; rotatable auger means; means mounting said auger means on said bin so that said auger means may extend into at least the up per portion of said pile, and for movement in an orbital path about an axis, said auger means being inclined downwardly and in the direction of its movement and sub- 7 stantially tangentially of said path; and means operatively connected to said auger means for rotating the latter, rotation of said auger means when the latter extends into piled grain effecting a reaction between said grain and said auger means tending to move the latter along said path.

4. Apparatus for stirring material such as grain or the like stored in a container, said apparatus comprising supporting means; means for mounting said supporting means above the level of material to be stirred in said container for movement in an orbital path; a stirring auger; means mounting said auger on said supporting means with the auger axis extending downwardly into said container and with said auger axis being movable radially inwardly and outwardly with respect to the orbital path of movement of said supporting means, said auger being inclined to the vertical with respect to its movement in the orbital path; and driving means for simultaneously driving said supporting means unidirectionally in said orbital path, moving said auger mounting means and said auger radially serially inwardly and outwardly with respect to said orbital path, and rotating said auger.

References Cited by the Examiner UNITED STATES PATENTS 277,876 5/83 Brown 3418l 380,588 4/88 Notll 34181 649,351 5/00 Prinz 34181 X 1,958,301 5/34 Greene 34181 X 1,981,603 11/34 Mustonen 34-481 X 1,996,142 4/35 Burke 10498 1,999,564 4/35 Hartung 259-102 2,304,772 12/42 Allardice et a1. 259-10 X FOREIGN PATENTS 34,128 7/85 Germany.

1,081,834 5/60 Germany.

NORMAN YUDKOFF, Primary Examiner.

20 CHARLES OCONNELL, Examiner. 

1. GRAIN STORING AND DRYING APPARATUS COMPRISING A BIN HAVING A PERFORATED BOTTOM ON WHICH GRAIN MAY BE PILED; AIR DRYING MEANS; MEANS FOR FORCING DRIED AIR THROUGH SAID PERFORATED BOTTOM AND THROUGH THE PILE OF GRAIN; GRAIN STIRRING MEANS; MEANS MOUNTING SAID SURRING MEANS FOR SPIRALLING MOVEMENT THROUGH SAID GRAIN ABOUT A VERTICAL AXIS WITHIN SAID BIN; DRIVING MEANS FOR REVOLVING SAID STIRRING MEANS ABOUT SAID VERTICAL AXIS IN A SINGLE DIRECTION OF REVOLUTION; AND MEANS OPERABLE WHILE SAID STIRRING MEANS IS REVOLVEING ABOUT SAID AXIS FOR SERIALLY MOVING SAID STIRRING MEANS RADIALLY TOWARD AND RADIALLY AWAY FROM SAID AXIS WHEREBY SAID STIRRING MEANS WILL SERIALLY TRACE A SPIRAL PATH OF EVER DECREASING RADII FOLLOWED BY TRACING A SPIRAL PATH OF EVER INCREASING RADII, WILL THEN REPEAT TRACING A PATH OF EVER DECREASING RADII FOLLOWED BY TRACING A PATH OF EVER INCREASING RADII, AND SO ON. 